rondy

FWIW: I (@rondy) am not the creator of the content shared here, which is an excerpt from Edmond Lau's book. I simply copied and pasted it from another location and saved it as a personal note, before it gained popularity on news.ycombinator.com. Unfortunately, I cannot recall the exact origin of the original source, nor was I able to find the author's name, so I am can't provide the appropriate credits.

---

Effective Engineer - Notes

• By Edmond Lau
• Highly Recommended 👍
• http://www.theeffectiveengineer.com/

What's an Effective Engineer?

jboner

Latency Comparison Numbers (~2012)
----------------------------------
L1 cache reference                           0.5 ns
Branch mispredict                            5   ns
L2 cache reference                           7   ns                      14x L1 cache
Mutex lock/unlock                           25   ns
Main memory reference                      100   ns                      20x L2 cache, 200x L1 cache
Compress 1K bytes with Zippy             3,000   ns        3 us
Send 1K bytes over 1 Gbps network       10,000   ns       10 us
Read 4K randomly from SSD*             150,000   ns      150 us          ~1GB/sec SSD

myronmarston

# 1) Use VCR.use_cassette in your let block. This will use
# the cassette just for requests made by creating bar, not
# for anything else in your test.
let(:foo) { VCR.use_cassette("foo") { create(:bar) } }
it "uses foo" do
  foo
end

# 2) Wrap the it block that uses #foo in VCR.use_cassette.

dperini

//
// Regular Expression for URL validation
//
// Author: Diego Perini
// Created: 2010/12/05
// Updated: 2018/09/12
// License: MIT
//
// Copyright (c) 2010-2018 Diego Perini (http://www.iport.it)
//

ragingwind

Backend Architectures

Twitter

ror, scala, jetty, erlang, thrift, mongrel, comet server, my-sql, memchached, varnish, kestrel(mq), starling, gizzard, cassandra, hadoop, vertica, munin, nagios, awstats

• Introduce Gizzard of Twitter - 트위터의 새로운 분산 관리 라이브러리 Gizzard를 소개합니다.
• The Architecture Twitter Uses to Deal with 150M Active Users, 300K QPS, a 22 MB/S Firehose, and Send Tweets in Under 5 Seconds
• Scaling Twitter: Making Twitter 10000 Percent Faster

oodavid

Deploy your site with git

This gist assumes:

• you have a local git repo
• with an online remote repository (github / bitbucket etc)
• and a cloud server (Rackspace cloud / Amazon EC2 etc)
  • your (PHP) scripts are served from /var/www/html/
  • your webpages are executed by apache
• apache's home directory is /var/www/

otobrglez

# Simple Recommendation Engine in Ruby
# Visit: http://otobrglez.opalab.com
# Author: Oto Brglez <otobrglez@gmail.com>

class Book < Struct.new(:title)

  def words
    @words ||= self.title.gsub(/[a-zA-Z]{3,}/).map(&:downcase).uniq.sort
  end

korakot

# install chromium, its driver, and selenium
!apt update
!apt install libu2f-udev libvulkan1
!wget https://dl.google.com/linux/direct/google-chrome-stable_current_amd64.deb
!dpkg -i google-chrome-stable_current_amd64.deb
!wget https://edgedl.me.gvt1.com/edgedl/chrome/chrome-for-testing/118.0.5993.70/linux64/chromedriver-linux64.zip
!unzip -j chromedriver-linux64.zip chromedriver-linux64/chromedriver -d /usr/local/bin/
!pip install selenium chromedriver_autoinstaller

# set options to be headless, ..

merqlove

namespace :optimization do
  desc "Provide DB vacuum for production environment"
  task :vacuum => :environment do
    begin
      tables = ActiveRecord::Base.connection.tables
      tables.each do |table|
        ActiveRecord::Base.connection.execute("VACUUM FULL ANALYZE #{table};")
      end
    rescue Exception => exc
      Rails.logger.error("Database VACUUM error: #{exc.message}")

stevenharman

Heroku Release Phase + Review Apps + Rails

This is a simplified, but fairly thorough, set of scripts and configuration to enable Heroku Release Phase for Rails apps. Further, this particular set up plays nicely with Heroku Review Apps in that the release phase script will:

1. Fail, loudly, if the DB does not yet exist.
2. Load the DB schema if the current schema version (as determined by bin/rails db:version) is 0.
3. Run DB migrations otherwise.

For a "normal" app that usually means it will run the DB migrations.